The invention discloses a cationic type covalent triazine framework material, a preparation method and an application thereof in iodine adsorption, and belongs to the technical field of porous organicpolymer materials. The invention aims to provide the efficient cationic type covalent triazine framework material and the preparation method thereof. The method includes, firstly, preparing two monomers of 1,3-bis (4-cyanophenyl)-1H-imidazole-3-ammonium chloride and 1,3-bis (4-cyanophenyl)-1H-imidazole-3-ammonium hexafluorophosphate; and further polymerizing on the basis of the monomers to obtain the cationic type covalent triazine framework material. The material has the characteristics of permanent pore structure, high specific surface area, good chemical and thermodynamic stability, strong iodine adsorption capacity, low requirements on instruments and equipment, simple synthesis process, strong repeatability and the like.